Chain grate



Sept. 13, 1932. H. "B. HOLT 1,877,320

crmm GRATE Original Filed May 18. 1929 2 sheets-sheet 1 5 4 000000000OOQQOOQOOQOOQOOOOOOOOOOOOOO & IIIIMIIIIIIIIT INVENTOR Harri B HoH:

b @44 Mao/201% his offer-h8g5 H. B. HOLT CHAIN GRAIE Sept. 13, 1932.

Original Filed lay 18, 1929 2 Sheets-Sheet 2 INVENTOR Harris Holt,

Patented Sept. 13, 1932 unirs 1 area twee HARRIS IB. HOLT, or nonivronr, PENNSYLVANIA, ASSIGNOR r ROSEDALEFOUNDRY} a; p p ncnrnn COMPANY, A conronerron or PENNSYLVANIA Rfiled for abandonedapplication Serial No. 3644096, fileclIVIay 18, 1929, and in Canada January 22, 1931. v I

This application filed May 5, 1932. Serial l\To 609,544.

This invention relates to improvements in chain-grates such as are commonly employed in the furnaces of power plants and other like places, and consists insuch an organization of the chain-grate as to provide for the discharge of ashes at the frontof the furnace; that'is to say, at that end ofthe furnace, ordinarily .the accessible end,'at which the fuel is introduced.

The invention is illustrated in the accompanying drawings. Figure I is a view in longitudinal section of a furnace equipped with the chain-grate of my invention; Figure II is a view in side elevation of a single link of the chain-grate of the particular form which I prefer to employ; Figure III is a view in plan of the link articulated in its place in the grate structure; Figure IV is a v fragmentary view in vertical section of the rear portion of the grate in assembly with a certain block with which the grate there cooperates; Figure V is a view similar to Figure IV, illustrating a modification and an elaboration in detail.

The endless, travelling grate 1, borne on a sprocket roller 2 and a smooth roller 3, is

disposed in upper and lower reaches in and 16, respectively, as is shown in Figure I. As seen inFigure I, the direction of travel of the upper reach of the cl1ain-grate is from left to right, and the direction of the lower returnreach is from right to left. As is here shown and ordinarily would be the case, the two reaches extend in substantially hori zontal position. At the front of the furmice-the left-hand end, as seen in Figure Ithe grate extends beyond the furnace, and above this extension a coal chute 4 is shown to be arranged. Ihis chute is accessible to receive its charge, and the chute is so arranged as to deliver upon the advancing grate a layer of fuel of desired depth. This layer of fuel the grate carries from left to right, into and through the furnace chamber. In its progress through the furnace chamber the fuel is'burned; and at the right-hand end of the structure the grate, rounding roller 3, carries the ashes downwardly. It is common to have an ash pit at this remote end of the structure, the right-hand end as seen in Figure I. My invention consists in such a particular structure and co-operation of parts as;

will effect the carrying of the ash by the travelling grat'efrom the remote end of the T structure forward again in right-to left direction to the'front of the furnace and the delivery of the ashes to an ash pit 5 situated there.

1 Referring to Figures Ii, III and Iv, the

grate will be seen tobe made up of links llof elongate form provided with terminal eyes 12 through which eyes rods 13 may be threaded in usual manner to form the articulated structure. Preferably, as shown in Fig. III,

the fuel-sustaining portions 14: of the links are double the width of the portions which are perforated with the eyes 12, and the links are assembled uponthe' rods 13 in the usual echelon formation, indicated in Fig. IV. The I fuel-supporting face of each link is made up of aplurality of'imperfo'rate areas an area 14 extends in parallelism with the plane of advance; an area 15'anterior to area 14 is forward-1y concave and meets area 14 perpendicularl at the angle a, as shown in Fig.II;'a"

third area 16is rearwardly inclined from area 1 1, V In consequence of the particular formation of the link, the assembled grate,

as is best illustrated in Fig. IV, has a fuelsupporting surface the plane of whose continuity'is interrupted with pockets 17. These pockets are so particularly shaped and dis posed that they carry forward material resting in them, and, when it comes to the delivery of the ashes, these pockets, co-oper ating with the parts presently to be described, drag the ashes in the direction of the advance of-the grate over' a co-operating surface. 7 The so I widened fuel-supporting faces of the link are minutely shaped to facilitate the passage of streams of combustion-sustaining air through the grate and between thelinks, but with this matter of aeration of fuel the present invention is not immediately concerned. So far as concerns the supporting of the'fuel, the upper surface of the grate, throughoutits upper reach, affords substantially'continuous support. 7 r

Means are provided to co-operate with the endless travelling grate'throughout its re loo 7 turn reach, and to carry the ashes to a point of discharge at the front of the furnace. These means include a block 6 arranged adj acent the smooth roller 3 and having a surface curved to parallelism with the grate as it rounds the roller 3, and against which-the ashes borne by the grate are pressed as the grate advances. From the lower end ofthe block-6 and; in parallelism with the lower reach of the grate a plate 7 extendslforwarde ly to the ash pit 5.

As the travelling grate rounds the roller 3' with a burden of ashes restinglargelyinthe pockets '17, this burden is shiftedto bear upon the rounded face of block 6, and then in turn to bear upon the the plane surface of plate 7 The block 6 and the plate-'7 are so spacedfrom the travelling grate that the recessed grate engaging the-ashes shall drag them over the surface of these parts to the forward end of plate 7, where the ashes fall freely into the pit 5.

' The rounded surface of the block .6 is preferably provided with ribs Glextending in the direction'of grate travel. Such ribs are effective to cause the travelling grate to exert upon the burden of ashes strains, such; as to efiect the crushing of lumps of clinker and the like. i

In operation the travelling grate carries fuel from chute 4 in the manner described through the burning region within the furnace, and from the burning region it. carries lower reach of the grate, the grate surface affording substantially continuous support for fuel and being provided with pockets each of which extends transversely and in continuity throughout the width of the grate, the pocket-wall on the leading side being inclined at a smaller angle to the general plane of the grate surface, and the pocket-wallonthe following side'b'eing inclined at, a larger angletolthe. general plane of the grate surface.

'2. A furnace structure including an endless chain grate arranged in upper and lower reaches with rounded communicating ends, and a confining wall for ashes spaced from the ashes into the run-way defined by and be- I 'tweeniits own body and thesurfaces of block 6 and of plate 7. By virtue of its pocketed formation, the grate drags the body of ashes in more or less segregated masses through thisrun-way and delivers them to the pit 5.- AS it so operates, it effects crushing of clinke'rs and larger lumps, this crushing op eration. being generally accomplished] between the gratestructure itself and the face of block 6. v a

, An elaboration of the means for crushing lumps of ash and clinkers, which may be preferred in'the use of coals of certain grades and qualities, is shown in Fig. V, where in the face of the block 6 an idly turning c0rrugated roller 62 is set. With this roller the travelling grate co-operates more certainly to accomplish the crushing described. It will be observed that, regardingthe grate as a dragging member, for dragging the ashes over plate 7, each pocket has a posterior wall, concave to thedirection of progress, which meets-the plane of plate 7 perpendicularly, as shown in Fig. IV. This application is a substitute for my application for chain grate, filed May 18, 1929, Serial. No. 864,096. r V Iclaimas my invention:

1. A furnace structure including an endless chain grate arranged in upper andxlower reaches and a drag plate underlyingthe 

